WO2012175471A1

WO2012175471A1 - Actuator system and operating method for an actuator system

Info

Publication number: WO2012175471A1
Application number: PCT/EP2012/061649
Authority: WO
Inventors: Heinz-Anton Schneider; Christof Maron
Original assignee: Continental Teves Ag & Co. Ohg
Priority date: 2011-06-20
Filing date: 2012-06-19
Publication date: 2012-12-27
Also published as: EP2720919B1; CN103619680A; EP2720919A1; DE102011077786A1; US20140196994A1; KR20140034250A; US10232836B2; CN103619680B; KR101960114B1

Abstract

The invention relates to an actuator system and to an operating method for an actuator system, in particular an electromechanical parking brake system (1), comprising an actuator (5), wherein the actuator (5) is driven by a direct current motor (28) that can be driven in both directions of rotation, wherein a control unit (10) for controlling the movement of the direct current motor (28) in an open-loop or closed-loop manner is provided. The core of the invention is that one or more pieces of information are supplied to a control unit (10, ECU), said information allowing the application force exerted by the electromotive actuator (5) to be determined and compared to a predetermined minimum application force, and wherein the control unit (10, ECU) emits at least one piece of information, signal or the like for requesting an auxiliary actuation to peripheral systems, components and/or electronic control units after the target to actual value comparison has shown that the determined, set application force is smaller than the predetermined minimum application force.

Description

Actuator system and operating method for an actuator system

The invention relates to an actuator system, in particular electromechanical brake system having the features of the preamble of patent claim 1 and an operating method thereto.

An electromechanically actuated motor vehicle brake with an actuator is known in principle, and comprises an electric motor which is to be controlled by an electronic control unit (ECU). The vehicle brake has an actuating element (brake piston), which acts on at least ei ^¬ NEN friction lining and is displaceable from a rest position into an actuating position in which the actuating element applies the friction lining against a friction ring. The actuating element (brake piston) can be actuated by an electric motor-gear unit. The friction lining can thereby be metered applied to a friction ring.

Actuators in motor vehicles, in particular actuators for actuating motor vehicle brakes, are exposed to very different stresses and operating temperatures. In order to always switch off the vehicle safely, a defined application force must be provided, which can be performed by a predetermined, defined energization of the actuator in the context of a control or regulation of the actuator with the inclusion of current operating parameters.

DE 103 61 042 B3 discloses a method for controlling an electrically actuated parking brake. This method is used to compensate for aging and wear-related changes in the application force or of changes in the application force due to changes in the resistance and / or the temperature of the electric motor or a loss of efficiency, the Abschaltström the electric motor varies. There is the criticism that the method described above allows an actuator in principle a deterioration in efficiency, while to other vehicle systems (electrical system) increased Leistungsanfor ^¬ changes are made.

The object of the invention is to provide an improved actuator system and a particularly efficient, improved operating method for an actuator system, which enables a system improvement on the basis of a holistic approach, and thereby enables an improved integration in the vehicle.

The object is achieved by the characterizing features of Pa ^¬ tentanspruch 1. Accordingly, the control unit is able to perform a desired-actual value comparison and to request a Hilfsbetäti ^¬ supply depending on the result. This serves to reduce an electrical vehicle electrical system load.

In a further embodiment of the invention, it is provided that the control unit is supplied by the actuator system as an input ^¬ size information about a hydraulically controlled pressure. Accordingly, it is proposed that the energy saving support demand for another energy source is evaluated, and that a support from demand in ^¬ dependence is of the evaluation by the control unit knows ^¬ tergegeben, modified or revised.

Further details of the invention will become apparent from dependent claims in connection with the description with reference to the drawings. In the drawing shows each schematically:

Fig. 1 shows a known brake system comprising components of the parking brake, and

Fig. 2 is a schematic diagram to illustrate the applied motor current I over the time t at

Clamp.

A known motor vehicle brake system 1 according to FIG. 1 has, at least for each wheel of an axle, an actuator 5 which is connected in each case to a control unit 10 via one or more electrical supply lines 7. Fig. 1 further shows an electrical actuation of the control unit 10 via a (possibly multiple redundant trained) elekt ^¬ cal line 12 to the operating switch 14 of the parking brake with which the application or release of the parking brake by the driver of the motor vehicle can be initiated. The control unit 10 comprises an electric clamp ^¬ voltage supply 15th Furthermore, the actuators 5 sensors S, in particular temperature sensors,

Have speed sensors, force sensors or similar encoders, switches or actuators connected via additional data lines 6 for communicating information with the control unit 10. Each actuator includes an electric motor 28 and a gear G and possibly a caliper housing.

A universal application of an electronically controlled actuator 5 in motor vehicles, as well as a detection of other or additional physical operating and characteristic quantities, is conceivable without departing from the basic idea of the invention.

FIG. 2 illustrates a characteristic profile of a clamping force F, a position S of a spindle, brake linings 2, 3, etc., current consumption I and the voltage U during the application of an actuator 5, in each case over the time t. In the control unit 10, in particular the current consumption I is observed for this purpose. The clamping force F is shown in phantom in Figure 2, the position S is dash-dotted ^¬ and the power consumption I of the electromechanical actuator 15 is defined by a sequence of "+" -.. Depicted symbols Only the voltage U is illustrated in Figure 2 as a solid. Line shown.

At the beginning, the actuator 5 is in the released state, ie, the position S is "zero" and the application force F is also "zero", as shown at position 20 at the time ^¬ point to. Point 21 illustrates that at the beginning of a brake-application at a relatively high ^¬ load current is required to overcome the mechanical inertia, and also to move from the state of static friction in a state of kinetic friction. At the time ti ends this start-up phase and it is followed by the time t _2, a so-called landing phase. At time point t ^¬ ₂ are reasonable brake pads at the friction partners 4 2.3 sets and accordingly increases with increasing distance s the clamping force F, as shown at numeral 23. The application force F increases during this Zuspannphase until the time t3 with a first slope. Almost parallel to this is the current consumption I. At time t3, the slope of the application force F kinks and the course of current consumption I describes from point 23 a turning point, because elasticities such as in particular a biased Fe ^¬ derpaket is compressed with a defined-predetermined spring stiffness to paragraph 24. At time t4, the application force is so great that the elasticity is completely compressed - in block form. The current consumption I be therefore ^¬ writes starting at time t ₄ a turning point and follows almost parallel to the again sharply increasing clamping force F.

At time ts, the current consumption I reaches the maximum current level I _max . At the same time, there is no further displacement or contact of brake pads 2, 3, and the position S also no longer changes after time ts. Therefore, the generated application force F remains constant after the time ts, which is legally defined

Application force has been reached, and the actuator is tet abgeschal ^¬.

The actuator system is structurally designed so that the brake actuator (brake piston) a superposition of hydraulic energy and (electro-) mechanical energy is possible such that electromechanical Spannkraftan ^¬ parts, electro-hydraulic clamping force components and purely hyd ^¬ raulische clamping force components can be impressed bundled. On this basis, the invention enables a Improved actuator drive by being able, according to the invention, not only to recognize if and when there is a need for additional support by another energy source, but to perform an additional check based on at least one setpoint-actual value comparison, so that it is checked whether a demand, revised or ^¬ play, by an energy-intensive, electrohydraulic Zuspannkraftaufbau optionally is changed from ^¬ by this additional energy demand is satisfied for example by mechanical driver energy, so that the process an improved energy management ^¬ ment enables and protect an electric vehicle on-board network can. Before the control unit actuates any other energy source for clamping force assistance so to speak automated, there is a Bewer ^¬ tion and assessment of the prevailing environment and conditions ^{according to the} invention. It can be assessed whether and how the situation can be improved by intelligent, possibly networked and temporally differentiated demand for auxiliary power by peripheral systems, actuators, vehicle drivers. In this case, it is thus verified whether a basically demanded demand for support is absolutely necessary, or whether and how a modified Actu ^¬ tion by an ESP system by externally actuated electrohydraulic pressure build-up is executed. So it is in order to save energy or conservation of electrical utilities / electrical system allows a request for support can be virtually discarded completely. In other words, it is made possible by the invention to adapt a minimum clamping force to a certain extent adaptive as a function of vehicle and ambient conditions. Consequently, the invention can also provide that as fallback solution with overloaded electrical system, low vehicle mass and load in conjunction with a slope ^¬ or slope-free parking space a needs-based, minimally selected clamping force is defined. It is mög ^¬ Lich, adjust the clamping force adaptive to the absolutely necessary load conditions while protecting the electrical system. As a result, unnecessary energy consumption is reduced, and unnecessary stress on vehicle components due to constant stress in the amount of the legally defined minimum clamping force is avoided. As a result, by the force required to Zuspannvorgänge, Ener ^¬ sumption is lowered and the parking brake system is protected by demand loading without compromising security.

It is possible to provide the desired-actual value comparison cyclically periodically with a predetermined, constant or variable clock frequency.

The control unit 10, ECU is supplied as an input current ^{¬ a requirement} of the actuator 5. For assessing and evaluating changes so the time (Zuspann-) behavior of the actuator system, the control unit evaluates 10, ECU the temporal change of the power demand from the Ak ^¬ tuator 5 out. In this context, the control unit 10, ECU, for execution of the setpoint-actual value comparison at least one information about the nature and extent of a service brake operation, in particular at least one ge ^¬ measured, hydraulic pressure value supplied to one

Determine total clamping force. Furthermore, a check is made as to how the measured hydraulic pressure value with a hydraulic pressure in a cylinder, as in particular master cylinder and / or wheel brake cylinder, correlated. The Mindestzuspannkraft can adaptively Variegated ^¬ bar be provided such is carried out that the electromotive actuator activation as a function of a plurality of cycles performed in target Istwertvergleichen adaptive-variably controlled or regulated.

The control and regulating operations of the control unit 10, ECU, such as in particular a demand to override in Ab ^¬ dependence on the operating pheriebedingungen, Fahrzeugzeug- and / or peri ^¬ is executed or controlled by crosslinking with peripheral components controlled. In particular, the electronic control unit 10, ECU with at least one electronic control unit of a Betriebsbremssys ^¬ tems for the purpose of transmission and / or exchange of data, signals and the like networked (bus system) is provided, and wherein the service brake system by the electronic control ^¬ unit (as a hydraulic actuator) can be externally operated. It is possible in this context that the electronic control unit (10, ECU) of the electronic control unit on the basis of / of the desired-actual value comparisons predetermines at least one desired value for the control of the hydraulic devices ^¬ rule actuator. It is provided that the desired value defines a hydraulic pressure, which is performed by the actuator. The target value may be fixed or variable Stored ^¬ chert amendable provided.

In connection with the use of the invention is to protect the electrical system possible that a demand for override is canceled or suppressed when the control unit 10, ECU information vorlie ^¬ gen that demand an override not to Reaching the minimum clamping force leads, and wherein the actuator system additionally emits an error message.

The invention can in principle be used in electric parking brakes built calipers ver ^¬ add (integrated here means hydraulic force and electromechanical force generated act on a common force transmitting member for establishing a Bremssattelspan- force) and is independent of a concrete embodiment of the control unit (One Control unit exclusively for EPB functions or an integrated control unit EPB and ABS / ESP functions) for controlling the electro-mechanical actuators of the parking brake.

In principle, however, the invention is for the

Energiemanagment in any actuator or for use in electromechanically actuated vehicle brakes in principle suitable.

Reference sign list

I motor vehicle brake system

2.3 friction partner (friction lining)

4 friction partners (brake disk / friction ring)

5 actuator

6 data line

7 supply line

8 electronics unit (actuator)

9 electronics unit (ECU)

10 control unit (ECU)

II suppression agent

12 supply line

13 hydraulic line

14 operating switch

15 power supply

20-24 marker points

28 electric motor

MPA motor pump unit

I electricity

n speed (actuator activity) t time

tO until ti time

S sensor

v temperature

F clamping force

s way

U voltage

G gearbox

Claims

claims

1. Actuator system and operating method for a

Actuator system, in particular service or parking brake ^¬ comprising at least one electronically ^¬ controlled electric motor actuator (5) and at least one electronic control unit (10, ECU), which is connected via at least one electrical supply line (7) with the actuator (5) and wherein the control unit (10, ECU) is connected to one or more switches, encoders, sensors S and / or electrical actuators, and at least one microprocessor with implemented software for implementing a control strategy for the purpose of controlled or regulated electrical supply to the actuator ( 5), and wherein the actuator system insbesonde ^¬ re than electromechanically actuated motor vehicle ^¬ braking system (1) is formed comprising an electrically actuable wheel brake to generate a defined brake application force between the friction partners (2,3,4), characterized in that the control unit (10 , ECU) one or more pieces of information n are supplied as an input variable, which allow to determine the of the electromotive actuator (5) exerted application force, and having a predetermined Mindestzuspannkraft to verglei ^¬ surfaces, and wherein the control unit (10, ECU) at least one information signal or the like to the demand an auxiliary operation to peripheral systems, components and / or electronic control units emitted after the set-actual value comparison has revealed that the determined, set by the actuator (5) Clamping force is less than the predetermined minimum clamping force.

2. Actuator system and operating method for a

Actuator system according to claim 1, characterized in that the desired-actual value comparison by the control unit (10, ECU) in cycles regularly, in particular periodically, with a predetermined clock frequency, repeatedly executed.

3. Actuator system and operating method for a

Actuator system according to claim 1 and 2, characterized in that the demand for a Hilfsbetäti ^¬ tion, depending on the setpoint-actual value comparisons in the cycles, is continued and amended emitted.

4. Actuator system and operating method for a

Actuator system according to one or more of claims 1-3, characterized in that the control unit (10, ECU) as an input quantity, a power demand from the actuator (5) is supplied.

5. Actuator system and operating method for a

Actuator system according to claim 4, characterized in that the control unit (10, ECU) and observes a temporal change of the power demand of the actuator (5) ermit ^¬ telt.

6. Actuator system and operating method for a

Actuator system according to one or more of the preceding Henden claims, characterized in that the control unit (10, ECU), for execution of the target actual value comparison, at least one information about the nature and extent of a service brake operation, in particular at least one measured, hydraulic pressure value is supplied to determine a Summenzuspannkraft.

Actuator system and operating method for a

Actuator system according to one or more of the preceding claims, characterized in that the at least one measured hydraulic pressure value correlates with a hydraulic pressure in a cylinder, in particular master cylinder and / or wheel brake cylinder.

Actuator system and operating method for a

Actuator system according to one or more of the preceding claims, characterized in that the Mindestzuspannkraft is provided adaptively changeable, and that the electromotive actuator operation in response to a plurality of executed in cycles target-actual value comparisons is executed adaptively-controlled or controlled.

Actuator system and operating method for a

Actuator system according to one or more of the preceding claims, characterized in that the demand for auxiliary operation is carried out controlled or regulated as a function of the operating, vehicle and / or peripheral conditions. Actuator system and operating method for a

Actuator system actuator is provided to one or more of the preceding claims, characterized in that the electronic control unit (10, ECU) is provided cross-linked with at least one electronic control unit of an operation ^¬ brake system that elekt ^¬ tronic control unit for controlling a ge ^¬ secreted , And that the elec tronic control unit (10, ECU) of the electronic control unit at least one setpoint for Ansteue ^¬ tion of the actuator pretending.

Actuator system and operating method for a

Actuator system according to one or more of the preceding claims, characterized in that the

Setpoint defines a hydraulic pressure that is performed by the actuator.

Actuator system and operating method for a

Setpoint fixed, specify, is.

Actuator system and operating method for a

Actuator system according to one or more of the preceding claims, characterized in that the desired value is variably provided as a function of the reference Istwertvergleic.

Actuator system and operating method for a

Actuator system according to one or more of the preceding claims 1-13, characterized in that a demand for auxiliary operation is aborted or suppressed if the control unit (10, ECU) has in ^¬ formations that a demand of a

Help not to reach the

Minimum clamping force leads, and wherein the

Actuator additionally emitted an error message.